<template>
  <el-breadcrumb class="app-breadcrumb" separator="/">
    <transition-group appear name="breadcrumb">
      <el-breadcrumb-item v-for="(item,index) in levelList" :key="item.path">
        <span
          v-if="item.redirect === 'noRedirect' || index == levelList.length - 1"
          class="no-redirect"
        >{{ item.meta.title }}</span>
        <a v-else @click.prevent="handleLink(item)">{{ item.meta.title }}</a>
      </el-breadcrumb-item>
    </transition-group>
  </el-breadcrumb>
</template>

<script lang="ts">
import * as pathToRegexp from 'path-to-regexp'
import { ref, defineComponent, watch, Ref } from 'vue'
import { useRoute, useRouter, RouteLocationMatched } from 'vue-router'


export default defineComponent({
  setup() {
    const levelList: Ref<RouteLocationMatched[]> = ref([])
    const route = useRoute()
    const router = useRouter()

    function isDashboard(route: RouteLocationMatched) {
      const name = route && route.name as string
      if (!name) {
        return false
      }
      return name.trim().toLocaleLowerCase() === 'Dashboard'.toLocaleLowerCase()
    }

    function getBreadcrumb() {
      // only show routes with meta.title
      let matched = route.matched.filter(item => item.meta && item.meta.title)
      const first = matched[0]

      if (!isDashboard(first)) {
        matched = [({ path: '/dashboard', meta: { title: 'Dashboard' } } as unknown as RouteLocationMatched)].concat(matched)
      }
      levelList.value = matched.filter(item => item.meta && item.meta.title && item.meta.breadcrumb !== false)
    }
    getBreadcrumb()
    watch(() => route.path, () => getBreadcrumb())

    function pathCompile(path: string) {
      // To solve this problem https://github.com/PanJiaChen/vue-element-admin/issues/561
      const { params } = route
      var toPath = pathToRegexp.compile(path)
      return toPath(params)
    }
    function handleLink(item: RouteLocationMatched) {
      const { redirect, path } = item

      if (redirect) {
        router.push(redirect.toString())
        return
      }
      router.push(pathCompile(path))
    }

    return { levelList, handleLink }
  }
})
</script>

<style lang="scss" scoped >
.app-breadcrumb.el-breadcrumb {
  display: inline-block;
  font-size: 14px;
  line-height: 50px;
  margin-left: 8px;

  .no-redirect {
    color: #97a8be;
    cursor: text;
  }
}
</style>
